1. Field of the Invention
The present invention relates to a printing apparatus which prints on the basis of print data, a control method therefor, and a program.
2. Description of the Related Art
In the commercial printing industry, a third party (customer or client) places an order to create a printed product (e.g., magazine, newspaper, brochure, advertisement, or gravure), and a printed product desired by the client is created. The printed product is delivered to the client to get the fee from the client. Even now, the commercial printing industry mainly uses large-scale printing apparatuses such as an offset reproduction printing press.
In the commercial printing industry, work proceeds through various processes. The processes include, for example, entry, design & layout, comprehensive layout (presentation using a printer output), proofreading (layout correction and color correction), proof (proof print), block copy preparation, printing, post process, and shipping. When the above-mentioned printing press is used, a block copy must be prepared. Once the block copy is prepared, it is difficult and disadvantageous in cost to correct the block copy. This problem arises from the fact that careful proofreading, i.e., layout check and color confirmation are indispensable.
As described above, in this industry, large-scale apparatuses are needed, and a long time is taken to create a printed product desired by a client. Work operations require expert knowledge and know-how of experts called craftsmen.
Nowadays, with the advent of high-speed and high-quality electrophotographic and inkjet printing apparatuses, a print-on-demand business category is present against the conventional printing industry. Print-on-demand will be abbreviated as POD hereinafter.
The POD intends to group jobs handled by a printing apparatus into jobs of relatively small lots and print the jobs in a short delivery period without using any large-scale apparatus or system. The POD implements digital printing using electronic data by making the best of digital image forming apparatuses such as a digital copying machine and digital multi-function peripheral. The POD market of the POD business category is being developed. In this POD market, printing is merged with digitization more than in the conventional printing industry, and management and control using computers become widespread. By utilizing the computers, POD printing is coming close to a given level of the printing industry.
In this background, the POD market provides PFP which is a printing service for a copy/print shop, and CRD which is an in-house printing service. The PFP stands for Print For Pay, and the CRD stands for Centralized Reproduction Department.
The advantages of the PFP and CRD are a lower cost and shorter delivery period in comparison with offset printing. In the POD market, it is important how to shorten the downtime of the printing apparatus and increase the printing productivity. In the POD market, a dedicated operator often performs a printing process.
A configuration for increasing the printing productivity is disclosed in, e.g., Japanese Patent Application Laid-Open No. 2001-96870. In Japanese Patent Application Laid-Open No. 2001-96870, when job A having no stapling instruction and job B having a stapling instruction are successively processed, an initial operation on stapling of subsequent job B is executed parallel to a process for preceding job A. The parallel operation shortens the process of job B after the process of job A.
In Japanese Patent Application Laid-Open No. 2001-96870, it is examined to increase the productivity of a plurality of jobs by the system.
In a printing environment such as the POD environment, it is an important factor for a business chance how to efficiently process many print jobs in order to meet various requests from various users (clients). It is desired to provide a convenient, user-friendly printing system capable of flexibly coping with this situation. For this purpose, examinations should be made on the assumption of an operation environment, practices, needs, and the like at an actual site.
Assume that a print job of many pages is requested from the customer or many jobs are processed. In this situation, the working efficiency may decrease if the operator always monitors the printing apparatus until all print jobs are completed. At the work site, therefore, it is expected that the operator moves away from the printing apparatus and performs another work even during printing by the apparatus. At this time, if an error factor such as absence of print sheets or absence of toner used for printing occurs in the printing apparatus, it is expected that the printing apparatus temporarily interrupts the printing process.
Assume that a subsequent print job waits after the interrupted print job in this situation, and the subsequent job is free from any printing interruption factor. Even in this situation, it is expected that processes for all print jobs by the printing apparatus stop due to the error factor generated in the current print job. In this case, the printing process of the printing apparatus may stop until the operator cancels the error factor or printing of the print job is canceled. As a result, the productivity of print jobs may be influenced in the whole system.